Brant

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Brant Helms Conference

• Chapters 10 11

Andrew Knoll, MD UCI Radiology October 22, 2008
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Preliminary Quiz
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Case 1
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Case 2
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Case 3
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Case 4
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Case 5
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Case 6
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Clinical Syndromes

• Myelopathy Emergency MRI
• Cord compromise (compression, intrinsic lesion,
  inflammatory process)
• Bowel/bladder incontinence, spasticity, weakness,
  ataxia
• May develop sensory/motor level, but lesion may
  be several levels higher than expected
• Radiculopathy Not an emergency
• Impingement of spinal nerve, usually sec to
  degenerative changes
• Sensory/motor level correlates well with lesion

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Imaging modalities / techniques

• MR study of choice for evaluating myelopathy and
  radiculopathy
• CT myelography if MR contraindicated (plain film
  myelography rarely done)
• CT better than MR for spondylolysis (MR not very
  good), and for detection of calcification
  (tumors, OPLL, spurs, bone fragments following
  trauma)

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Differential Diagnosis by Location

• Intramedullary (within cord itself) cord
  appears widened and CSF space appears thinned in
  all views
• DDX Damn Cord is Trouble
• Demyelin. Dz (MS, ADEM, transverse myelitis)
• Cysts (syringohydromyelia, neuroepithelial cyst)
• Infarct ( also AVM/AVF)
• Tumor (AHEM mnemonic)
• Intradural Extramedullary widened csf/contrast
  column adjacent to the mass, csf/contrast forms
  acute angles with the mass
• DDX Meningioma, schwannoma, neurofibroma (Big
  3), also dermoid, epidermoid, lipoma, arachnoid
  cyst, drop met, AVM

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Differential Diagnosis by Location

• Extradural or epidural (outside the dural sac,
  within spinal canal) csf forms obtuse angle
  with mass, mass effaces epidural fat and thins
  csf space adj. to the mass
• DDX think degenerative and nondegenerative
• Degen herniated disc, synovial cyst, osteophyte
• Nondegen epidural hematoma, epidural abscess,
  lymphoma/chloroma, mets, myeloma, EM
  hematopoiesis

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Inflammatory cord lesions

• Myelitis inflam process directly involving
  cord, results in myelopathy
• Transverse myelitis nonspecific myelitis
  confined to specific level(s) not a disease but
  rather a category of diseases
• On imaging, it is not transverse variable
  size, but usually extends 3 or 4 spinal levels

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Inflammatory cord lesions

• MS / Devics
• High T2, usually w/o signif. change in cord
  caliber
• In acute phase, may see cord expansion,
  enhancement (tumefactive), or restricted
  diffusion
• Remember to look upstairs
• SLE
• Necrotizing arteritis ? cord ischemia
• Diffuse areas of high T2 edema, usually w/o
  enhancement less well-defined than MS plaques
  
• Dramatic improvement with steroids
• Rhematoid Arthritis
• Pannus (extradural mass) destroys transverse
  ligament of C1, dens slides posteriorly resulting
  in cord compression (extradural process)
  symptoms worsen on flexion
• DDX fibrous pseudotumor seen with os odontoideum
  and other unstable spinal anatomy

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Inflammatory cord lesions

• Radiation myelitis
• Peaks 6-12 mos post XRT
• High T2 /- enhancement
• Clue is marrow change (fatty replacement)
• Postviral myelitis (ADEM)
• Clinical high fever, followed in 4 weeks by
  rapid onset motor, sensory, and autonomic
  deficits referable to specific level(s)
  (transverse myelitis)
• Also can occur following vaccinations
• Focal areas of edema and cord expansion
• In contradistinction to Guillain-Barre, which is
  ascending paralysis due to peripheral nerve
  involvement (also postviral)
• Arachnoiditis (postsurgical, infectious, etc.)
• Clumping of cauda equina nerve roots, empty sac
• Neurosarcoid multiple nodular enhancing areas
• Pantopaque arachnoiditis
• Recognize high signal on T1 (lipid-based contrast)

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Postviral myelitis

• DDx
• MS / Devics
• SLE
• Sarcoid
• Infarct
• Neoplasm

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Guillain-Barre Syndrome

• DDx
• Infection (e.g., CMV)
• Meningeal carcinomatosis
• Granulomatous disease

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Postoperative lumbar arachnoiditis
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Infection

• Osteomyelitis/discitis
• Hematogenous infection ? endplate ? disc ?
  vertebral body (osteomyelitis/discitis complex) ?
  seed epidural space ? extend to paraspinal ST
  (e.g., psoas)
• In children, disc has rich blood supply and may
  be primarily infected
• Epidural abscess
• Often extend several vertebral levels
• Frequently cause cord compression
• Subdural empyema (rare) usually assoc. with
  violation of the dura (surgery), may progress to
  meningitis
• Cord Abscess (rare) appears similar to brain
  abscess

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Infection

• Pyogenic
• Staph most common, followed by Gram negs.
• Salmonella assoc c sickle cell dz
• Severe back pain unrelieved by positioning (vs.
  DJD)
• On plain film, typical to see disc destruction ?
  disc space narrowing and irregularity (vs.
  sparing of disc with TB)
• MRI abnormal signal and enhancement in disc and
  bone, /- paraspinous ST mass

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Pyogenic osteomyelitis/discitis
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Non-Pyogenic Infections

• More indolent course
• Diagnostic challenge b/c immunosuppressed pts.
  are at risk for both infxn and neoplasm
  (mets/lymphoma) often requires biopsy
• TB (Potts)
• Slow collapse of usually more than one vert
  bodies, spreads subligamentous
• Leads to gibbus deformity, cord compression
• Tends to spare disc
• Psoas abscess common
• May also cause meningitis
• Fungal
• Clasically Candida and Aspergillus in
  immunosupressed pts, also cocci, blastomycosis,
  and cryptococcus
• Cocci spares disc like TB
• May be hard to distinguish from neoplasm

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Tuberculous spondylitis (Potts Dz)

• Ddx
• Fungal
• Mets
• Myeloma
• Lymphoma
• Pyogenic infxn

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Neoplasms Intramedullary

• Classic plain film finding focal widening of
  interpedicular distance
• AHEM (astrocytoma, hemangioblastoma, ependymoma,
  mets)
• Astrocytoma
• 75 cervical and upper thoracic rare in
  conus/filum
• Fusiform cord widening and T2 hyperintensity
  extending several levels
• Can be exophytic, mimic extramedullary
• Ependymoma
• Most common cord tumor
• Usually benign
• 60 in conus / filum
• Filum is usually myxopapillary type
• Hemorrhage and cystic changes common
• Hemangioblastoma
• Densly enhancing nidus /- cyst (very classic)
• Assoc c Von Hipple Lindau
• 40 extramedullary
• 20 multiple

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Ependymoma
Differentation of Ependymoma and Astrocytoma is
Very Difficult !!!
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Astrocytoma
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Hemangioblastoma associated syrinx
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Neoplasms Intradural/Extramedullary

• Meningioma
• Most commonly in the thoracic region
• 80 in women
• May have extradural component
• May have dural tail and/or calcifications
• Homogeneous enhancement (just like cranial ones)
• Nerve Sheath Tumors (Schwannoma/Neurofibroma)
• Histologic difference in that neurofibroma
  diffusely infiltrates nerve w/o encapsulated
  margin while schwannoma remains outside n. (same
  on imaging)
• Either can have classic dumbbell shape with
  extension through neural foramen

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Thoracic meningioma
Note flaring of csf space adj to mass
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Cystic Schwannoma
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Neurofibromatosis Type 1
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Neoplasms Intradural/Extramedullary

• Intrathecal drop mets
• From primary CNS tumors (medullo, ependymoma,
  germinoma, choroid plexus carcinoma)
• Leptomeningeal metastases (breast, lung,
  leukemia)
• Inflammatory rxn carcinomatous meningitis
• Multiple intradural nodules
• DDX infectious meningitis, blood

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Leptomeningeal Metastases
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Extradural Masses

• Most commonly degenerative (disc, etc.), followed
  by neoplasm (mets most common breast, lung
  prostate)
• Mets typically low T1 high T2 within vertebrae
  (vs. the ubiquitous hemangioma high T1) and
  usually enhance
• Exception Sclerotic mets (prostate) may be low
  on all sequences
• Compression fracture
• Ddx osteoporosis, mets, infection
• Signs of mets noncontiguous vertebral levels,
  spares discs, , marked involvement of pedicles

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(No Transcript)
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Benign compression fracture
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Pathologic fracture (lung met)
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Other Extradural masses

• Direct extension of paraspinous tumor
• Retroperitoneal/mediastinal tumors
• Neuroblastoma, ganglioneuroma, lymphoma, Pancoast
  lung tumors
• Frequently infiltrate canal through neural
  foramina
• Leukemia
• Diffuse, even replacement of marrow by cellular
  tumor
• Chloroma solid leukemic infiltrate may involve
  epidural space and cause cord compression
• Lymphoma
• 2 presentations metastatic vertebral body
  involvement or invasion through neural foramina
• Often extensive epidural/paraspinous mass
  associated with it, can mimic infxn such as TB
• Multiple myeloma
• Multiple low T1 foci or diffuse low T1 signal in
  spine (On T1, vertebrae should always be
  brighter than disc)
• Myelofibrosis
• Very dark marrow on T1 and T2 (ddx prostate
  mets)
• Primary Bone Tumor

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Vascular

• Cord infarct (rare)
• Usually s/p thoracic surgery (aortic aneurysm
  repair), but can also be thromboembolic
• Appears bright on T2 ? enhancement ? later
  myelomalacia
• Vascular malformations
• Intramedullary AVM congenital nidus of abnormal
  vessels
• Cord hemorrhage ischemia sec to steal
  phenomenon
• Extramedullary usually AVF (SDAVF)
• Venous HTN ? cord congestion / edema
• High T2, expansion, and enhancement in conus, /-
  dilated veins
• Pitfall CSF pulsation artifact (particularly in
  thoracic spine) may be confused with dilated
  spinal veins limitation of MR

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Cord infarct
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Spinal AVM

• MR
• Flow voids
• Edema
• Punctate enhancement
• Angio
• Enlarged anterior spinal artery (of Adamkiewicz)
• Nidus
• Venous shunting

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Syringohydromyelia (syrinx)

• Hydromyelia dilated central canal, lined by
  ependyma
• Syringomyelia cavity outside central canal,
  lined by glia
• Difficult to distinguish, hence
  syringohydromyelia
• Etiologies Chiari (usually I), trauma, tumor,
  inflammation, ischemia

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Syrinx secondary to Chiari I
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Congenital lesions

• Pediatric intraspinal masses are most commonly
  congenital
• Tethered cord
• Conus normally at L2 in newborns, T12/L1 adults
• Below that level tethered, but hard to tell
  exact level b/c tethered roots form a taut mass
  therefore must follow serially
• May present in adulthood with gait abnormalities
• Assoc with spinal dysraphism, lipoma
• Fatty filum
• Not associated with tethering
• Asymptomatic
• May have to follow

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Congenital lesions

• Caudal regression syndrome
• Distal L spine sacrum hypoplastic or absent
• Blunted appearance of conus
• Associated with cardiac renal anomalies
  (mesoderm problem)
• Assoc c maternal diabetes
• Cystic lesions
• Perineural (Tarlov) cystincidental usually
  sacral represent dilated nerve root sleeves
• Anterior sacral meningocele
• Arachnoid cyst isointense to CSF
• Ddx epidermoid
• Complication of LP (acquired arachnoid cyst)
• Neurenteric cyst (notochord communicates with
  foregut)
• Look for canal of Kovalevsky

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Congenital lesions

• Congenital scoliosis
• If severe or early or associated with vertebral
  anomalies on plain film, MR is indicated to rule
  out intraspinal pathology
• Diastematomyelia
• Sagittal cleft (split cord)
• Midline bony / fibrocartilagenous spur (plain
  films, CT)
• Diplomyelia- extremely rare

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Caudal regression syndrome
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Extradural Arachnoid Cyst
Note effacement of epidural fat and narrowing of
CSF space adjacent to the mass
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Diastematomyelia (and tethered cord)
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Trauma

• Cord contusion
• Usually (not always) occur at site of fx sec to
  bony impingement
• Edema is bad blood is really bad (irreversible)
• Later, myelomalacia potentially can enlarge c
  csf entry, evolve into syrinx
• EDH
• Much more common than SDH (opposite of brain)
• Venous bleeding
• Nerve root avulsion
• Most common in c-spine
• Classic cause birth trauma (shoulder dystocia)
• CSF leaks into epidural space through rent in
  dura and arachnoid from missing nerve
  (pseudomeningocele)
• see dilated lat recess w/o nerve roots

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Epidural Hematoma
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Chapter 11

• Lumbar Spine Disc Disease and Stenosis

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Degenerative disc disease

• Terminology bulge, broad-based protrusion,
  protrusion, extrusion, sequestration (free
  fragment)
• Surgeons dont care what you call it. Only
  concerned with whether the abnormality is
  responsible for pts symptoms
• Most important to describe effect on canal and
  foramina
• Extrusion disc material above or below disc
  space
• Free fragments
• Signal often different from parent disc
• Lateral disc (beyond neural foramen) mimic sx of
  central protrusion one level cephalad because
  they affect the root that has already exited
  spinal canal
• Ex central disc protrusion at L3/4 impinges on
  L4 nerve root, but far lateral disc at L4/5 also
  can impinge on L4 nerve root

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Disc extrusion with free fragment
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Far lateral disc herniation
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Spinal Stenosis

• Central spinal canal stenosis
• Measurements of spinal canal not considered
  valuable
• Instead, mention if thecal sac is round or
  compressed and give subjective assessment of
  severity
• Most common causes are hyertrophic facet djd and
  buckling/hypertophy of ligamentum flavum, /-
  superimposed disc protrusion/bulge
• Less common causes Pagets, achondroplasia,
  post-traumatic, severe spondylolisthesis
• Often exacerbated by background of congenitally
  short pedicles
• Lateral recess stenosis ( where the nerve roots
  lie after leaving thecal sac but before entering
  neural foramen
• Same etiologies as neural foraminal stenosis
• Neural foraminal stenosis
• In L spine, nerve root in the sup portion of NF
  and disc inferior portion
• Most common cause is djd of facets, less commonly
  due to lateral disc protrusion, free fragment or
  postop scarring

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Spondylolysis / spondylolisthesis

• Spondylolysis
• CT superior to MR for detection
• Best seen on axial slices as laminar defect
  (looks like facet joint but not at disc level)
• Presumably stress fx
• Isolated spondylolysis usually asymptomatic
• Spondylolisthesis
• Bilateral pars defects
• Pseudospondylolisthesis due to facet dz (mild,
  most common at L4-5)
• Divide vert into fourths (grade 1-4)
• Significant listhesis may cause canal and/or
  neuroforaminal stenosis

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Spondylolysis / spondylolisthesis
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Marrow Endplate Changes (Modic)

• Type 1 low T1, high T2 (edema)
• Inflam response to DDD
• Ddx infxn (disc bright on T2 c infxn)
• Type 2 high T1, high T2 (fat)
• Most common
• Type 3 low T1, low T2 (Sclerosis)

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Quiz

• Do you have the spine?

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Case 1

• Findings
• Scalloping of posterior vertebral bodies by dural
  ectasia
• Lateral meningocele

Neurofibromatosis Type 1
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Case 2
Findings enhancement of ventral nerves
Guillain-Barre Syndrome
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Case 3
Spinal dural AV Fistula
Findings enhancement and high T2 singal in the
conus and serpentine flow voids which enhance.
MRA shows serpentine high sig. DDx SDAVF, AVM
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Case 4
Hemangioblastomas in von Hippel-Lindau disease
Findings multiple enhancing intradural (probably
intramedullary) nodules in C, T, and L spine,
with associated lumbar syrinx
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Case 5

• Findings
• Multiple low T1 high T2 enhancing lesions
  throughout
• Epidural (subligamentous) enhancement
• Paraspinal peripherally enhancing mass
• Ddx
• TB
• Fungal
• Mets
• Myeloma
• Lymphoma

Tuberculous spondylitis
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Case 6

• Findings
• Intradural / extramedullary CSF-signal lesion
  with peripheral enhancement, compressing conus
• Ddx
• Cystic Schwannoma
• Infected arachnoid cyst
• Epidermoid
• Necrotic met
• Necrotic exophytic cord tumor

Schwannoma
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Case 7
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Case 8